Marks & Spencer staff in Ireland have voted to strike over the firm's plans to close its final-salary retirement scheme.

An overwhelming 94% of workers voted in favour of strike action, which is planned for Saturday 7 December and two further days before Christmas at 17 stores across the country.

The Mandate trade union, which represents most of the firm's 2,300 staff, said the retailer's move to close the scheme to new and existing staff in favour of a stock-market related scheme was "unacceptable".

M&S, which has shut its UK final-salary pension only to new members, said the decision in Ireland followed similar cutbacks by rival employers. Earlier this year it closed four shops that it said were unprofitable and proposed opening a new store in Limerick following a strategic review.

The retailer said: "These changes are in line with the Irish market. The changes we are making will help manage these costs for the long term and ensure our business is best set up for the future."

"M&S has done all it can to try and move this situation forward so we are extremely disappointed that the company has been given notice that strike action has been called."

The union said the pension scheme had a €17m (£14m) surplus at its last valuation and was viable over the longer term.